PTSD is recognized by the Department of Defense, the Department of Veterans Affairs, and the National Institute of Mental Health as a major medical issue for both deployed and returning U.S. troops. In particular, recent studies indicate that the incidence of PTSD among Iraq and Afghanistan veterans is 20% and may reach 35%, which is a rate 4-7 times higher than the general population. PTSD is not only an illness that affects military personnel; the NIMH reports that almost eight million Americans suffer from this disorder and that it ranks among the most common psychiatric conditions in the country. PTSD is characterized by diminished emotional capacity, compromised relationships with family and friends, reduced interest in activities that bring enjoyment, irritability, increased aggression, and sometimes violent behavior. Additional disorders often co-occur with PTSD, including depression, substance abuse, other anxiety disorders, anger and impulsivity disorders, and the like. Like other mental health conditions, the consequences of PTSD extend beyond the patient to their families as well. Not only are there increased long-term medical costs, there also is diminished earning capacity and adverse impacts on quality of life. In combination, these circumstances produce a cycle of spiraling demand for Federal assistance, lost earnings, and escalating, ongoing social and economic costs. Improved treatments for PTSD and depression, especially during the first two years after deployment could reduce medical treatment costs for the US military (projected at $4.0 to $6.2 billion) by 25% to 40%.
Current drug therapies for PTSD rely on existing, repurposed antidepresants and anxiolytics that have not demonstrated sufficient efficacy, include undesirable side effects, and have been recognized to be further limited due to compliance issues; see, for example, Keane, et al. Posttraumatic stress disorder: etiology, epidemiology, and treatment outcome. Annu Rev Clin Psychol, 2: 61-97 (2006); Lader, Effectiveness of benzodiazepines: do they work or not? Expert Rev Neurother, 8(8):1189-91 (2008); Marks, et al., Paroxetine: safety and tolerability issues. Expert Opin Drug Saf, 7(6):783-94 (2008). The foregoing publications, and each additional publication cited herein is incoporated herein by reference. Whether it is the complexity of PTSD or differences in the underlying neurobiology of the disorder, available drugs offer limited relief. A new approach to pharmacotherapy is needed for significant improvement in clinical outcomes.
It has been discovered herein that PTSD and related diseases and disorders are treatable with selective vasopressin V1a antagonists of the formula
and pharmaceutically acceptable salts thereof; wherein
A is a carboxylic acid, an ester, or an amide;
B is a carboxylic acid, an ester, or an amide; or B is an alcohol or thiol, or a derivative thereof;
R1 is hydrogen or C1-C6 alkyl;
R2 is hydrogen, alkyl, alkenyl, alkynyl, alkoxy, alkylthio, halo, haloalkyl, cyano, formyl, alkylcarbonyl, or a substituent selected from the group consisting of —CO2R8, —CONR8R8′, and —NR8(COR9); where R8 and R8′ are each independently selected from hydrogen, alkyl, cycloalkyl, optionally substituted aryl, or optionally substituted arylalkyl; or R8 and R8′ are taken together with the attached nitrogen atom to form a heterocyclyl group; and where R9 is selected from hydrogen, alkyl, cycloalkyl, alkoxyalkyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, and R8R8′N—(C1-C4 alkyl);
R3 is an amino, amido, acylamido, or ureido group, which is optionally substituted; or R3 is a nitrogen-containing heterocyclyl group attached at a nitrogen atom; and
R4 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, alkylcarbonyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted arylhaloalkyl, optionally substituted arylalkoxyalkyl, optionally substituted arylalkenyl, optionally substituted arylhaloalkenyl, or optionally substituted arylalkynyl.